Thomas cooper



T. COOPER.

FRICTION CLUTCH.

APPLICATION FILED OCT. 31, 1917.

1,306,302. Patented June 10, 1919.

THOMAS COOPER, OF NORFOLK, ENGLAND.-

FRICTION-CLUTCH.

Specification of Letters Patent.

Patented June to, 1919.

Application filed October 31, 1917. Serial No. 199,475.

To all wkoin it may concern: I

Be it known that I, 'THoMAs COOPER, .a subject of the King of Great Britain, and resident of The South House, Kings Lynn, Norfolk, England, have invented new and useful Improvements in Friction-Clutches, of which the following is a specification;

Friction clutches to which the present improvements are applicable are of the type which comprises plates arranged side by side and attached respectively to the driving and driven members which are locked together by pressure applied to the sides of the said plates. There may be any convenient number of the said plates.

My invention resides in the device which I emplo for imparting the pressure necessary or, forcing the plates into frictional and binding contact.

The device comprises rollers arranged as hereafter explained cooperating with inclined surfaces carried by a fixed abutment.

The rollers may conveniently be arranged in sets'of three, each set being mounted to turn freely on an axle carried by a air of arms forminga kind of stirrup. Sne of these rollers, say the middle one, w-i11 be adapted to take. against its inclined abut- -ment, while the others will bear against the pressure plate of the friction clutch.

This may be arranged by having the middle roller of larger diameter than'the others which are the same in diameter and by having a groove or recess in the pressure plate wide and deeplen'ough to provide a' The clearance for the saidlarger roller.

smaller rollers when in contact with the pressure plate will not reach the abutment,

so that the of the axle. a

The inclined surfaces, the number. of

pressure is imparted by means i which will correspond with the number-of sets of rollers, are also curved and preferably take the form of hollow backed rams inserted in cylindrical boxes through the bottom of which extend the ends of the shanks of the rams. This permits of the employment-of compression springs within the boxes held to the. required degree of compression by-nuts screwed on to the ends of the shanks which protrude through the bottom of the boxes.

The boxes above mentioned areinserted in ,the fixed abutment and being screwthreaded can be adjusted to advance or retract the inclined surfaces as may be re- .endwise thereon,

quired. The compression of the springs within the boxes being once set to the requlred pressure no further adjustment of the said springs is necessary or desirable. The springs supply the'pressure needed for the clutch and have sufliclent yield to permit the rollers to ride over the highest point or peak of the curved incline and thus a locked point is provided for the rollers.

The stirrups carrying the rollers are arranged in any suitable number about. the

driving or driven shaft and are furnished with means for extending them in a radial direction from positions nearly parallel to the said shaft, to positions at right angles thereto or to positions beyond, where they will remain unsupported. During this movement the rollers operate as wedges between the surfaces of the abutment and the pressure plate of the clutch.

The arrangement has considerable advantages, in that it requires a comparatlvely small force to put very great frictional ressure into the clutch and further a 100 'ng position is provided for holding the plates without catches; and to effect dis-engagement a positive movement of the stirrups in r the reverse direction is necessary.

The clutch is capable of variat1on 1n detail without departing from the princlple of the invention which involves the employment of a combined roller and wedge action, the rollers being arranged in sets, the

members of which are divided into those 1s a cross section of part of the clutch and Fig. 2 an end view with the fixed abutment removed. r

a is alshaft which maybe regarded as the driving member. I) is a boss keyed thereto in any convenient manner, disks secured to the boss I) but free to slide the construction being such that the rotation of the shaft or will carry around with it the boss I; and the disk 0. d is a casing attached to the driven shaft or equivalent d and inclosing the disks c c are friction accompanying illustration, a larger roller f bein between two smaller rollers g g of equa diameter) are mounted loosely on the same axle h in a stirrup i. This stirrup i is pivoted to a collar j loose on the shaft a and capable of sliding lengthwise thereof.

k is an abutment having a fixed osition in relation to the casing 03. In the a utment 7c is screwed a box Z within which works a ram m pressed outward by spring a and retained by a nut o screwed into the threaded end of the shank p of the ram m which protrudes through the back of the box Z. The front of the ram is rounded.

In the end plate or disk 6 .Which belongs to the set of disks 6' carried by the casing 03 is a recess 9 opposite the roller f which recess is of suflicient depth and width to clear the said roller which is of larger diameter than the rollers g g on either side thereof. These rollers are able to touch the disk 6' and lie'snugly between the cheeks 'r 1' carried by the latter. I

To lock the clutch the collar 3' is moved in one direction viz: to the left of Fig. 1 and the stirrup c is thereby moved from .the

' dotted position to the position shown in the full lines.

The roller is thus forced against the inclined face of the ram m of the abutment k and the rollers g 9 take a bearing against the plate 6' on either side of the recess g. In this way pressure is brought to bear against the disks 0 and e which are forced together withthe pressure derived from the compression of the adjustable spring 1:. behind the ram. When pushed beyond the peak of the ram the rollers retain their position and the clutch remains locked without holding.

The movement of the collar 7' in the opposite direction takes the pressure off the plates and releases the clutch.

With this arrangement the clutch is very easy to manip'ulateand its operation is extremely eflicient.

The drawing above described illustrates only one operating device for the clutch but in practice any suitable number will be employed all similarly arranged at intervals and operated simultaneously by the collar j which is manipulated by a forked lever or equivalent device.

What I claim and desire to secure by Letters Patent of the United States is In a friction clutch having a set of rollers on the same axls, a bearing for imparting pressure, said bearing comprising an abutment, an abutment box adjustably secured thereto, a compresslon sprlng' withm the box, a ram having an inclined surface slidably mounted within the box for transmitting the pressure of the compression spring, and means for retaining the ram'within the box and for regulating the pressure of the said spring.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS COOPER.

Witnesses: I

ALFRED S. Brsrror, MAX. C. HOFMANN. 

